John Prendergast has spent his career trying to end genocide in Africa and to support peace and human-rights efforts. His work has propelled him into the center of mass atrocity, from which he has witnessed examples of both the best and worst of human character.

In this interview, which is part of our "On Leadership" video series, Prendergast talks about the experiences that shaped his leadership perspective — from meeting average citizens fighting for causes they believe in, to observing the humility of Nelson Mandela, to seeing up close the horrible power of dictators across Africa. Prendergast is a co-founder of the Enough Project, and has served as director of African affairs at the National Security Council and as an adviser at the State Department. He is also the author of several books, including the bestseller "Not on Our Watch."

Watch his video story above, or read the longer Q&A below. The conversation has been lightly edited for length and clarity.

Q. What has leadership come to mean to you?

A. Faced with a difficulty, faced with a challenge, faced with a catastrophe, you take a stand. You become, as Samantha Power calls it, an ‘upstander’ for the ideals that you cherish.

In human rights and peacemaking, it’s really about having a solid concrete goal — the reduction of human suffering somewhere in the world — and then doing what is required to get that goal achieved. Sometimes that means increasing public knowledge. Sometimes it’s going there and exposing the horrors of what’s happening on the ground. Sometimes it’s putting together a peace process. Sometimes it’s just standing up in a religious institution or a school or a community center and saying, “This thing is happening in the world, and we should do something about it. We should raise our voices against it.”

Q. What experiences from when you were younger shaped this view?

A. When I was 19 years old, I hitchhiked across the country to San Francisco. I dropped out of Georgetown University — probably a mistake, but there you go. I met three people, who were otherwise largely unknown to the world. One guy, Pat Goggins, was an encyclopedia salesman. His real goal and his real vocation were to help bring about peace in Northern Ireland. A second was a Jesuit priest, a guy called Father Paul Comiskey who was working in the jails in California. Thirdly, probably most importantly for me, was a fellow named Johnny Maher, who had been a former substance abuser. He decided to set up his own halfway house. He saw all the mistakes these places were making and wanted to do it better.

I’m 19 years old, terribly impressionable, wanting to see how the world — whether the world — in fact can be changed with all the ills and the horrors that we always hear about. Watching three people actually make a difference in the causes that they dedicated their lives to really had a profound impact on me. That made me a believer, and I have never shied away from that since then.

Q. You since went on to meet many well-known leaders like Nelson Mandela. What did you learn from him?

A. I spent a lot of time with President Mandela supporting his efforts in the peace process in Burundi. The thing that impressed me the most was his humility. He was potentially the world’s greatest and most revered leader, yet here was this guy who, when it was time for tea, would leap out of his chair – to the extent that he could leap at that point – shuffle over to the tea table, and pour everyone’s tea. He was always getting people’s coats, always opening the door, just endlessly putting everyone else’s needs and desires first. I never saw anything like it before, and I never saw anything like it since then.

Q. Being a human rights activist, how do you take frustration and grief and despair — things that for some people are immobilizing — and harness them into progress? Does that resilience come naturally to you?

A. There are two things that leap to mind when I think about countering despair and building hope.

The first is that when I go out to refugee camps and warzones and see the aftermath of terrible atrocities, inevitably someone will look at me very intensely and say, “Now that you know, you must do something. We’re relying on you.” With a mandate like that, I have no choice.

Secondly, I get a lot of hope from focusing on the positive stories, not just the ones of conflict. There are extraordinary turnaround stories throughout the African continent. Twenty-five years ago, Mozambique was torn to pieces by a horrific civil war. Today it’s one of the fastest-growing economies, not just in Africa but in the world. Liberia has the first elected woman president in all of Africa.

Yes, there are corruption issues. Yes, there are democratic deficits. But comparing the dark days of civil war to where they are today, the difference is staggering. So the good news stories give me hope that the Sudans and the Congos one day will also turn around.

Q. What do you believe in? The atrocities you’ve seen must have shaken your belief in some things and maybe strengthened your belief in others.

A. In this world, I guess I believe very strongly in leadership itself. I’ve seen President Mandela lead the Burundi negotiations. I’ve seen Anthony Lake, who was President Clinton’s special envoy trying to bring an end to the war between Ethiopia and Eritrea, lead a peace deal that has lasted to this day. I’ve seen a number of examples where an individual leading a peace process can actually make a profound difference to the future of millions and millions of people.

In the other world — for many, many years, because of the horrors that I witnessed and actually lived in during massive civil wars and atrocities, I lost complete faith in anything else. But maybe seven or eight years ago, I began to hear a little inner voice. That led me to re-explore my own faith tradition, which happened to be Christianity. I read the original texts of many things that had become lost to me, and those texts really spoke to me in a different and new way. I reestablished my own version of what my faith is in God, and in the overall plan.

I still don’t understand why suffering exists, but I do ultimately believe that we are our brother’s and sister’s keeper, that the Good Samaritan story has real relevance and meaning for the world we live in today, and that we have a responsibility to attempt, at least, to make the world better — and to make the lives of people around us better, especially those who are suffering.

Q. You’ve seen up close the worst side of leadership: people’s ability to mobilize others to kill. How has seeing that shaped your understanding of power and what humans are capable of?

A. I’ve seen orders given from the offices of prime ministers and presidents and defense ministers to commit genocide, to use rape as a tool of war, to subjugate populations for the benefit of the rulers. Having seen all that firsthand has given me the fortitude, when working on potential solutions to these problems, to not believe in the superficial reforms that some of these leaders undertake in order to fool the broader international community.

You see the regime in Sudan today attempting to undertake a national dialogue. But of course, look a little closer and you’ll see the groups that represent the vast majority of Sudan’s population are not welcome to be part of this. Or the conditions are not created — some level of freedom of speech, assembly and security — to allow them to be part. So it’s a dialogue amongst handpicked people in order to keep the status quo. I’m not easily taken in by these kinds of ploys, these diversionary tactics. It has pushed me not accept the superficial and the incremental.

Q. What do you think is the appropriate role for non-Africans in Africa’s struggles?

A. The bottom line in making a difference for those of us standing far, far away from where these terrible atrocities are occurring is to help redirect the spotlight — to shine it on particular places, often ones that are completely forgotten and have no strategic value to the great powers.

It’s not up to the person in Iowa or Arkansas necessarily to say, “Here’s my analysis of exactly what the United States government, or the United Nations, or the African Union, needs to do.” That’s for the institutions themselves to figure out. But it is up to us to demand that our elected leaders, or the companies that we buy products from, are doing something; and to show that we won’t stand idly by while these kinds of atrocities occur.

Q. What changes have you seen in yourself over the years, in terms of the evolution of your leadership skills and character?

A. Maybe how I deal with patience. I’ve become more impatient in my daily work. I’m probably a little too impatient with ensuring that the networks and organizations I’m part of are doing the right thing, and pushing the right thing the right way.

But I think I’ve become more patient and more tolerant about the idea that some of these conflicts are unfolding in a way that’s consistent with world history. South Sudan is the newest country in the world, born out of a conflict and then born back into conflict, tremendous instability and corruption. Well, most countries that are born out of conflict slide back into conflict before they finally move forward.

Sudan is 60 years old and South Sudan is three years old. Before the United States was 60, we had a terrible ethnic cleansing campaign against Native Americans and we had a trans-Atlantic slave trade. We hadn’t even fought our own civil war, which was in per capita terms one of the deadliest in world history. And centuries of instability, conflict and even genocide were part of the creation of the borders that we know today in Europe.

So understanding and being patient with the change that is taking place on the ground in Africa is probably where I’ve evolved a bit over the last 30 years.

Q. What’s the best piece of advice you have to give others?

A. One person, working in a community and a movement, can actually make a difference in the world, can actually make the world a better place.

Also in the series:

Like On Leadership? Follow us on Facebook and Twitter.